dictator vs viscount

dictator

noun
  • A tyrannical boss or authority figure. 

  • A person who dictates text (e.g. letters to a clerk). 

  • A totalitarian leader of a country, nation, or government. 

  • A magistrate without colleague in republican Ancient Rome, who held full executive authority for a term granted by the senate (legislature), typically to conduct a war. 

viscount

noun
  • A member of the peerage, above a baron but below a count or earl. 

  • Any of various nymphalid butterflies of the genus Tanaecia. Other butterflies in this genus are called earls and counts. 

How often have the words dictator and viscount occurred in a corpus of books? (source: Google Ngram Viewer )